The invention relates to an artificial acetabulum made of inner and outer shells.
The invention further relates to a method for the assembly and the alignment of the acetabulum in accordance with the invention.
EP-A-0 563 503 discloses a support device for an artificial acetabulum which comprises a semispherical support shell having support tabs with openings at the equatorial edge of the support shell. Such a support device is preferably implanted when the pelvic bone is damaged or severely deteriorated at the region which is to carry the hip joint, which in particular is often the case for reoperations. The support tabs are adapted to the shape of the pelvic bone by plastic deformation during the implantation, so that the support device can be anchored in regions of the pelvic bone capable of bearing a load with bone screws extending through the support tabs. Then a bone cement is applied which fills the clearance between the support shell and the bone tissue and which forms a cement bed within the support shell. Furthermore, an inner shell is set in the support shell, wherein the inner shell is positioned in an orthopedically favourable position, and the mutual position is fixed by the hardening of the bone cement. A disadvantage of such an acetabulum is that a bone cement is necessary for the attachment and alignment of the inner shell. It is known that the use of bone cement has several disadvantages, among other things the disadvantage that the pelvic bone is excessively damaged in unfavorable cases during a reoperation.